After her student, Sunset Shimmer, went through the mirror, Celestia spent the following years imagining what could happen if the unicorn finally returns. She even decided to keep track of them.

In fact, she wrote a whole book about it.

Edit: 11/11/16 WTF?! Feature Box? Thank you, guys!

When Sunset Shimmer decides to visit Equestria with her girlfriend – the human world’s Twilight Sparkle – she expects there to be some confusion. She doesn't expect to come home with a royal title.

Meanwhile, Equestria's Twilight Sparkle worries she's not evil enough.

Scavenging isn't just a hobby, it's a means of survival in the ruins of the old world. When you go scavenging, though, you'll never know what you'll find.

Pinkie Pie is about to find more than she bargained for.

Takes place in the same universe as Pieces of Me. Prior reading not necessary.

Special thanks to R5h, who helped make this story so much better than it was.

RCL featured!

Princess Celestia has finally decided to introduce her two prized pupils to each other, hoping that together they'll finally start to appreciate the beauty and magic of friendship. Sunset may be proud and brash, and Twilight might be obsessive and oblivious at times, but surely they'll get along fine, right?

They'll go above and beyond that in time, but the road they'll take to get there is a rocky one.

Written for Oroboro's Sunset Shipping Contest: Changing Seasons

Cover art by Novel-Idea
Original Sunset and Twilight image by Sikander-MLP

Featured on September 1, 2017!

Updated 10/27/17: Minor edits to existing chapters; 3 new chapters added (Reconciliation, The Twilight Zone, Sowing Seeds)
Updated 11/27/17: Cover art added!

Twilight and Sunset race against the clock to save Canterlot from a foe of unimaginable power… a romantic narrative.

Entry in Aragon's Comedy (is Serious Business) Contest with the prompt Today We Learned Something "Subtle."

Cover Design by Novel Idea
Twilight Sparkle Cutie Mark By Intbrony
Cover based on screenshot from Black Mesa

Beta Reader & Editor Credits
Cursori: Reader of Many a Pony Word
Little Tinker: Master of Systems at Poniverse & Scripting Engineer on The Manehattan Project
Ladrian: Resident Snarky Mistborn
Heartshine: Smol Pegsus, BIg Heart
Oroboro: Assassin of Extra Spa ces

Word Count: 12,000
Version: 3.1

While visiting each other at work, Rainbow Dash and Sunset Shimmer discover that they share a deep secret no one else must know.

A secret involving magical girls.

No, not that one.

The other one.

Part of the Montage Cinematic Universe.

Due to a slight misunderstanding involving Pinkie Pie, Sunset Shimmer finds herself on the receiving end of Limestone Pie's sisterly wrath. Because of this, she ends up suffering through the most stressful first week of school since her days at Celestia's school for gifted unicorns.

This story is a sequel to How Not To Use Your Royal Prerogative

  In an Equestria where the Sonic Rainboom never happened, Sunset Shimmer is the prized pupil of the Princess of the Sun. As Sunset struggles to make up for her past misdeeds and come to terms with the pony she wants to be, Celestia sends her to find the classic work The Application of Unified Harmony Magic from the Royal Canterlot Archives.
  Right after lunch, some meddling by her friends and meeting somepony with firsthoof experience of the Sunset she used to be.

Featured on Equestria Daily on August 18, 2016!
Appeared in the FimFiction Featured Box!

Cast: Sunset Shimmer, Moon Dancer, Minuette, Twilight Sparkle & Princess Celestia

Stories set in the Wavelengths Timeline in chronological order:

Origins Arc
The Alchemy of Chemistry
Bards of the Badlands
Grading on a Bell Curve
Habits of the Equestrian Phoenix
How Not To Use Your Royal Prerogative

Applications Arc
The Application of Unified Harmony Magics
Princess Celestia: A Brief History
The Cloudsdale Report

Dreamers Arc
Tactics of Snowbound Unicorns
A Study in Chaos Theory
Teahouses of Saddle Arabia
As the Raven Flies

Cover Credits
Cover Design by Amber Spark
Sunset Shimmer Vector by TigerBeetle
Pony SciTwi Vector by Osipush
Canterlot Bookshelves Vector by FavoriteArtMan
Sunset Shimmer Cutie Mark by MillennialDan

Beta Reader Credits
Ebon Quill - Worldbuilding Writer on The Manehattan Project
Quantum State - Technical Director of The Manehattan Project
The Albinocorn - Master of Sunset Shimmer Stories

Strongly Recommended Stories:
The Brightest and the Best by Pineta - The events in this story are considered to be completely canon to this timeline and explain Twilight's entrance exam to Celestia's School for Gifted Unicorns. I cannot recommend this story enough.
MLP Annual 2013 - "The Fall of Sunset Shimmer" - As above, the 8-page short comic in the beginning of the Annual is also considered to be canon, though with some major variations.

Version 3.0 Edit: Extensive grammatical and mechanics changes. Adjustment to timeline of Sunset's second mirror experience.

Set after Equestria Girls 3 (Spoilers ahead)

After the events of the Friendship Games, Sunset Shimmer and her new friend, Twilight Sparkle try to move on, but the pestering questions remained. What did Sunset turn into? Is Twilight safe from a demonic relapse? How did time loops keep Princess Twilight from responding?

With all three under one roof, the two Equestrians try to get to the bottom of this little mystery. Will they get at least a few answers?

Meanwhile, a new human has set their sights on Canterlot High

After so many years, Sunset Shimmer is finally ready to return to Equestria. At long last, she will be able to reconnect with the land she was born in and feel the magic flow through her body once more. Most of all, she’s ready to face the mentor she betrayed, to apologize for everything and beg for her forgiveness.

Princess Celestia is eager to see her old prodigal student as well. Finally, she will have the chance to forgive her and reaffirm her love for her. What’s more, she will finally be able to give Sunset Shimmer what she has earned for herself and fulfill all the dreams she had since she was a filly.

At least, that’s how it was supposed to go.

Cover art by Bluse